either there is a rock between the pad and the rotor or you really need to replace the pads!
Brakes
What would cause a grinding noise after a tire is replaced and the brakes are not worn?
Normally a rusty rotor would not make a grinding noise. A grinding noise from the brakes usually indicated that the pads or shoes are worn down.
Your pads or discs are worn. The brakes will fail soon if not replaced.
The brake pads are worn out and need to be replaced. The grinding sound means your brakes are about to stop working.
If you suspect something, get them checked. If you get vibration while applying the brakes, get them checked. If you get grinding noise from the brakes, get them checked.
Could be, in need of brakes or wheel bearing failure,
They could, yes.
Bearings, cv shaft, or brakes.
engine problems not trans.
no, that sounds like the brakes are grinding because the are ready to be changed, check them out immediately.
When it is time to change the brakes on your 2001 Mitsubishi Montero, they will make noises. There could be a grinding or squealing noise that you will hear.